<?php
/**
 * Created by PhpStorm.
 * User: dfh
 * Date: 2016/10/8
 * Time: 18:20
 */
header('Content-type:text/html;charset=utf-8');
function getFileExt($path){
    $ext=substr($path,strrpos($path,'.')+1);
    return $ext;
}
$path='C:images\apple.jpg';
$ext=getFileExt($path);
echo "<p>文件路径： $path</p>";
echo "<p>文件后缀：$ext </p>";